Space heaters

What we complained about just a few months ago, we long for once again as the days become shorter and the nights become colder: heat. As the cold weather settles in this winter, you may keep warmer while you work in the shop if you install an infrared space heater.

Infrared heaters work the same way the sun does. They are mounted overhead to direct infrared rays to heat objects such as the floor, people, machinery, and tools, which, in turn, heat the air. In a conventional forced air system, the stored heat (warm air) escapes when the doors are open. But with an infrared heating system, stored heat remains in the objects to help reheat the air quickly once the doors close.

Infrared heaters are either high or low intensity. They use a gas and air mixture for combustion to either heat a steel tube (low intensity) or a ceramic surface (high intensity). Both of these heaters can be used with natural gas or liquid propane.

High-intensity heaters require high mounting heights because of the hotter surface temperature. They're used for total building or spot heating. These heaters vent their exhaust products into the space and usually require an exhaust fan.

Low-intensity heaters have an internal fan that fires a flame 2 to 10 feet down a combustion chamber. As the tubing is heated, it emits infrared energy, which is then directed toward the floor by highly polished aluminum reflectors. These heaters have a lower surface temperature.

The majority of today's shops are better suited for low-intensity heaters.

There are three main features to consider when choosing the right low-intensity heater for your shop.

Burner design. Look for a swirl burner. This will help get a better gas and air mixture to push the flame further down the tube.

Tubing. Some models have a highly emissive black coating on the combustion and radiant tubes, which emits rays away from the tube for optimal output.

Reflectors. Get best performance out of a heater with highly polished, mirror-finish reflectors, which reflect rays downward.

Before purchasing any system, make sure the clearances to combustibles are taken into consideration. This is the minimum distance that must be maintained between the tube heater surface and any combustible product. Depending on the application and model, it's recommended that mounting heights be 10 feet or higher.

Two-stage heaters are becoming more popular as fuel costs go up. They utilize a two-stage gas valve that allows units to operate in high- and low-fire modes. This reduces the on/off cycles and can give up to 12% fuel savings over a single-stage heater.

Most low-intensity heaters are priced by tube length. Base cost of a standard, single-stage, 40-foot tube heater is about $1,000, depending on the features.

On the following page are examples of low-intensity infrared heaters.

What we complained about just a few months ago, we long for once again as the days become shorter and the nights become colder: heat. As the cold weather settles in this winter, you may keep warmer while you work in the shop if you install an infrared space heater.